WASHINGTON – The Supreme Court made it harder Monday to sue police for using deadly force against fleeing suspects, ruling that officers are immune from lawsuits unless it is “beyond debate” that a shooting was unjustified and clearly unreasonable.

By an 8-1 vote, the justices tossed out an excessive force suit against a Texas police officer who ignored his supervisor’s warning and took a high-powered rifle to a highway overpass to shoot at an approaching car. The officer said he hoped to stop the car but instead shot and killed the driver.

The high court said the benefit of the doubt in such cases always goes to the officer who sees a potentially dangerous situation. The court has “never found the use of deadly force in connection with a dangerous car chase to violate the Fourth Amendment,” the justices said in a 12-page opinion.

In cases where officers are not prosecuted, families sometimes sue in federal court and allege a violation of the Fourth Amendment’s ban on unreasonable searches and seizures.

The case decided Monday began when a man in Tulia, Texas, fled from a drive-in restaurant when police tried to arrest him. He was believed to be drunk and carrying a gun. He led officers on a nighttime chase that reached 110 miles per hour.

Texas state trooper Chadrin Mullenix heard about the chase over his radio and drove to a spot where officers were putting a strip of spikes to puncture the tires of the fleeing car. He had been criticized for not reacting decisively in the past, and he decided on his own to shoot at the fleeing car.

His commander advised him to “stand by” and “see if the spikes work first.” But Mullenix fired six shots and killed the driver, Israel Leija Jr.

His family sued, and a federal judge ruled the case could go to a jury to decide whether Mullenix’s actions were “reckless,” or reasonable under the circumstances. The 5th Circuit Court in a 2-1 decision agreed and said the officer was not entitled to immunity.

That decision was upheld by a 9-6 vote of the full appeals court. Texas then appealed Mullenix v. Luna but the justices ruled that the officer was immune from being sued.

“By the time Mullenix fired, Leija has led police on a 25-mile chase at extremely high speeds, was reportedly intoxicated, had twice threatened to shoot officers and was racing towards an officer’s location,” the court said. “Ultimately, whatever can be said of the wisdom of Mullenix’s choice, this court’s precedents do not place the conclusion that he acted unreasonably in these circumstances beyond debate.”

Sotomayor said the court “renders the protections of the 4th Amendment hollow” by sanctioning the officer’s “rogue conduct.” She noted he had not been trained in shooting at a fleeing car and was told not to shoot before the vehicle encountered the spikes across the highway.

“When Mullenix confronted his superior officer after the shooting, his first words were, ‘How’s that for proactive?’ ” she wrote. “The glib comment seems to me revealing of the culture this court’s decision supports when it calls it reasonable — or even reasonably reasonable — to use deadly force for no discernible gain and over a supervisor’s express order to ‘stand by.’ ”

The hunt for the serial bomber who has been leaving deadly explosives in packages on Austin doorsteps took a new, more sinister turn Monday when investigators said the fourth and latest blast was triggered along a street by a nearly invisible tripwire.